Flat or low-sloped roofs are often covered with polymeric membranes that protect the roof from environmental impact such as snow and rain. These polymeric membranes are typically manufactured and shipped in widths that are narrower than the roof surface to which they are installed. Accordingly, multiple membranes are often installed, and adjacent membranes are seamed together.
Pressure sensitive seam tapes are often employed for this purpose. Specifically, a pressure sensitive seam tape is applied to one surface of a membrane along a longitudinal edge, and an adjacent membrane is mated along its longitudinal edge to the top surface of the pressure sensitive seam tape to thereby form a seam.
Polymeric roofing membranes have historically been black in color. This color derives from the use of carbon black filler, which has been used to provide the membrane with advantageous mechanical properties. In warmer climates, however, it is believed that the black color absorbs solar energy and thereby places larger energy demands on those systems attempting to cool the building structures. In face of these concerns, the industry has provided white polymeric roofing membranes. While black tape can be used in conjunction with these white membranes, there is a desire to employ white tape in conjunction with white membranes.
Although some white tapes have been employed in the industry, they suffer several drawbacks. First, they lack the strength and mechanical properties associated with black adhesive tape. Second, they require significant cure time, which reduces manufacturing efficiencies and increases costs. Also, due to the level of curing, the compositions behave as thermoset materials and are therefore not reprocessable.
There is therefore a desire for pressure-sensitive white adhesive tape compositions that are more efficiently manufactured, are reprocessable, and demonstrate the mechanical and performance characteristics that have come to be expected from conventional tapes.